The Zeiss is by far the beter quality scope. the advantage of the leupold is the 30mm tube, not because it has larger internals for extra light transmission but it gives you more room for internal adjustment.
Zeiss should stick with 44mm Obj and get a 30mm tube, they would have a contender to take on the NXS and the like, but they won't do that because they have the Davari 6-24x56 with a 30mm tube that costs much more.
Pete

I have become a Conquest convert. I've been using IOR exclusively for around 10 years, and have become spoiled by this excellent euro glass. Over the past year I have bought two scopes for Kimber rifles. The IOR's in 4-14 are too big for an ultra light rifle so I compared Leuy side by side with Zeiss, and I bought Zeiss...twice!